Learning Speed Enhancement of Iterative Learning Control with Advanced Output Data based on Parameter Estimation

Learning speed enhancement is one of the most important issues in learning control. If we can improve both learning speed and tracking performance, it will be helpful to the applicability of learning control. Considering these facts, in this paper, we propose a learning speed enhancement scheme for iterative learning control with advanced output data (ADILC) based on parameter estimation. We consider linear discrete-time non-minimum phase (NMP) systems, whose model is unknown, except for the relative degree and the number of NMP zeros. In each iteration, estimates of the impulse response are obtained from input-output relationship. Then, learning gain matrix is calculated from the estimates, and by using new learning gain matrix, learning speed can be enhanced. Simulation results show that the learning speed has been enhanced by applying the proposed method

Wearable System for Daily Activity Recognition Using Inertial and Pressure Sensors of a Smart Band and Smart Shoes

Human Activity Recognition (HAR) is a challenging task in the field of human-related signal processing. Owing to the development of wearable sensing technology, an emerging research approach in HAR is to identify user-performed tasks by using data collected from wearable sensors. In this paper, we propose a novel system for monitoring and recognizing daily living activities using an off-the-shelf smart band and two smart shoes. The system aims at providing a useful tool for solving problems regarding body part placement, fusion of multimodal sensors and feature selection for a specific set of activities. The system collects inertial and plantar pressure data at wrist and foot to analyze and then, extract, select important features for recognition. We construct and compare two predictive models of classifying activities from the reduced feature set. A comparison of the classification for each wearable device and a fusion scheme is provided to identify the best body part for activity recognition: either the wrist or the feet. This comparison also demonstrated the effective HAR performance of the proposed system

Proposal for direct measurement of concurrence via visibility in a cavity QED system

An experimental scheme is proposed that allows direct measurement of the concurrence of a two-qubit cavity system. It is based on the cavity-QED technology using atoms as flying qubits and relies on the identity of the two-particle visibility of the atomic probability with the concurrence of the cavity system. The scheme works for any arbitrary pure initial state of the two-qubit cavity system.Comment: To appear in Physical Review A as a Rapid Comminicatio

Efficient hybrid organic-inorganic light emitting diodes with self-assembled dipole molecule deposited metal oxides

We investigate the effect of self-assembled dipole molecules (SADMs) on ZnO surface in hybrid organic-inorganic polymeric light-emitting diodes (HyPLEDs). Despite the SADM being extremely thin, the magnitude and orientation of SADM dipole moment effectively influenced the work function of the ZnO. As a consequence, the charge injection barrier between the conduction band of the ZnO and the lowest unoccupied molecular orbital of poly(9,9(')-dioctylfluorene)-co-benzothiadiazole could be efficiently controlled resulting that electron injection efficiency is remarkably enhanced. The HyPLEDs modified with a negative dipolar SADM exhibited enhanced device performances, which correspond to approximately a fourfold compared to those of unmodified HyPLEDs.open442

Happiness Education: International Use of Floating Signifiers in Education Policy // 행복교육: 교육정책에서의 부유기표와 의도적 언어 오용

Over the past decade, the concept of ‘happiness’ has been promoted by global agencies and national education authorities as a solution to the social problems of high teenager suicide rates, school bullying, and increasing socioeconomic polarization. This article considers ‘HEP: Happiness Education Policy’ in Korea, which was initiated by conservative Park Geun-hye administration (2013-2017) and partly succeeded by the subsequent progressive Moon Jae-in administration (2017-2022). The analysis reveals that the definitional ambiguity of happiness education has opened a space for multiple ascriptions of meanings, particularly those that are in line with the Park administration’s political and economic visions of ‘creative economy’. It also demonstrates that policies introduced as part of the HEP, such as the Free Semester initiative, have continued to be promoted and even expanded by Moon administration (2017-2022) despite their replacement of the signifier ‘happiness’ by ‘innovation’ and ‘future’. Therefore, this study suggests happiness education and, more lately, future education as good examples of ‘floating signifiers’; that is, by lacking a clear referent, they minimize political objections and legitimate the introduction and continuation of contested reforms. // 본 연구는 정책 전이 및 차용 이론에 근거하여 박근혜 정부의 ‘꿈과 끼를 키우는 행복교육 을 중심으로 정책 명칭과 관련된 언어의 의도적 오용 현상에 대해 분석하였다. 행복교육의 경우 OECD가 인도적 전환(humanitarian turn)을 시도하며 2012 국제 학업성취도 평가 (PISA)에 처음 도입한 행복 및 웰빙 문항들로 구체화되어 전이 되었다. 대한민국 학생들의 낮은 삶의 만족도에 대한 사회적 논란과 북유럽 교육에 대한 환상이 ‘대선’이라는 이벤트와 결합해 ‘행복 교육 이라는 대안으로 차용되었다. 최근 OECD에서는 ‘행복 및 ‘웰빙 이라는 용어들이 교육 성과의 척도를 넘어서 미래 우수 인력이 필수적으로 지녀야할 자질 및 역량으로 강조되는 등 인도적 전환의 색채가 지워지고 있다. 현 문재인 정부에서도 자유학년제 등 이전 정부의 행복교육 기조 아래 등장했던 정책과제들이 계속해서 이어지고 있으나, 기존 ‘행복 이라는 수식어는 미래, 혁신, 공정, 평등 등 새로운 용어로 변화하였다. 그러나 행복교육과 마찬가지로, ‘혁신 , ‘미래 등의 용어가 의미하는 바에 대해서는 의미가 불분명하여 해석 및 사용이 자의적으로 이루어지고 있다. 본 연구는 이런 수식어들이 교육정책 도입을 정당화하는 하나의 ‘부유 기표 (floating signifier)로 작용하고 있으며, 이와 같은 언어의 의도적 오용 현상은 암묵적인 양당의 합의 (bipartisanship)로 강화되었음을 밝혔다

Effect of Soft Errors in Iterative Learning Control and Compensation using Cross-layer Approach

In this paper, we study the effects of radiation-induced soft errors in iterative learning control(ILC) and present the compensation techniques to make the ILC systems robust against soft errors. Soft errors are transient faults, which occur temporarily in memories where the energetic particles strike the sensitive region in the transistors mainly under abnormal conditions such as high radiation, high temperature, and high pressure. These soft errors can cause bit value changes without any notification to the controller, affect the stability of the system, and result in catastrophic consequences. First, we investigate and analyze the effects of soft errors in the ILC systems. Our analytical study shows that when a single soft error occurs in the output data from the ILC, the performance of the learning control is significantly degraded. Second, we propose novel learning methods by incorporating the existing techniques across the system abstraction levels in the ILC to compensate for soft-error-induced incorrect output. The occurrence of soft errors is estimated by using a monotonic convergence of the erroneous outputs in a cross-layer manner, and our proposed methods can significantly reduce these negative impacts on the system performance. Under the assumption of soft error occurrence, our analytic study has proved the convergence of the proposed methods in the ILC systems and our simulation results show the effectiveness of the proposed methods to efficiently reduce the impacts of soft-error-induced outputs in the ILC systems

Laser mode-hopping assisted all-optical single beam pulsed atomic magnetometer

We demonstrate an all-optical single beam pulsed atomic magnetometer assisted by laser mode-hopping in a distributed Bragg reflector (DBR) laser. We implement a temporal sequence of the laser current; sinusoidal current modulation including the laser mode-hop current for synchronous optical pumping and the following constant current for paramagnetic Faraday rotation measurements to probe the free induction decay (FID) of transverse $^{87}$Rb spin polarization. Repetitive sudden frequency shifts of 20 GHz around the pressure-broadened $^{87}$Rb spectra originating from laser mode-hopping enables discontinuous optical pumping modulation with a large depth which enhances transverse spin polarization. We achieve a sensitivity of 3.77 pT/Hz$^{1/2}$ in a magnetic field of 14 $\mu$T, limited by the performance of the frequency counter. The Cramer-Rao lower bound (CRLB) of the sensitivity due to the non-magnetic noise such as photon shot-noise is 191 fT/Hz$^{1/2}$. Our approach based on laser mode-hopping can be applied to miniaturization of all-optical atomic magnetometers with sub-pT/Hz$^{1/2}$ sensitivities.Comment: 10 pages, 7 figure